Not applicable.
Not applicable.
This invention relates to dispensers for volatile materials such as insect control agents, scents and the like. In particular, the invention relates to dispensers that simultaneously dispense a volatile from a burnable coil and provide illumination.
There are a number of known dispensers for volatile ingredients that provide the additional feature of lighting the surrounding area. For example, U.S. Pat. No. 6,033,212 discloses a lantern that burns fuel for light. The flame is contained in a glass, transparent globe that is covered at its top. The cover has a slot that receives a pad impregnated with a volatile material having an insect control agent. The waste heat from the burning fuel exits the globe through the slot, which heats the pad and releases the volatile.
WO 00/78135 is another approach for mounting an insect repellent impregnated pad adjacent a flame. However, the types of pads used with these designs can be somewhat costly to produce, and in some cases place constraints on the type of active that can be used.
Citronella candles also provide both light and an insect repellent, and do so relatively inexpensively. However, exposed candle flames can be snuffed by the wind, and not all actives can survive being directly exposed to the candle flame when the candle wax is burnt.
Insect (e.g. mosquito) coils are also well known. They are typically a spiral coil of compressed, largely pulp material which has been impregnated with an insect control active. The coils can alternatively (or in addition) contain other active ingredients having different characteristics, such as aromatics or disinfectants. These coils are extremely inexpensive, and due to their slow burn rate provide overnight protection. They are particularly desirable because of their ability to disperse a variety of very effective insecticidal actives, at low cost.
However, these coils can be snuffed out if they are exposed to too much wind. Thus, it has been proposed to house them in apertured pots that can prevent outside gusts from directly reaching the coil. See e.g. U.S. Pat. No. 6,061,950. These pots also have the benefit of inhibiting persons from accidently bumping into these coils while they are burning. However, these pots dispense active at a slower rate than a coil that is directly open to the air, thus requiring them to be started somewhat earlier before using an area that might be insect infested.
Some other structures have been proposed to dispense insecticidal control agents by mounting materials containing them adjacent a heat source. See e.g. U.S. Pat. Nos. 692,075, 2,742,342 and 3,279,118. However, to date the art has not proposed a way to mount a mosquito coil in a lamp in a way in which the lamp flame assists in the dispersion of the vapors from the coil, without causing the entire coil to start burning out of sequence. Thus, there is still a need for an improved combined lamp and volatile dispensing device.
In one aspect the invention provides a lamp for dispensing a volatile material. There is a flame source, a chimney mounted around the flame source, a support mounted to the chimney above the flame source, and a burnable coil having a volatile material. The coil is positioned above the flame source so as to be exposed to heat therefrom.
In preferred forms the support is a plate having an opening (preferably a plurality of openings) there through. The support may also have a raised element (a spade) for supporting the coil, with the coil being mounted adjacent an upper opening of the chimney, vertically above the flame source. The chimney can have a radially inwardly extending ledge on which the support rests.
There is also preferably a skirt-like base upon which the flame source and chimney are mounted, an upper surface of the base having a recess for receiving a lower edge of the chimney. The base includes a plurality of openings positioned radially outside of the recess and a plurality of openings positioned radially inward of a radially outer edge of the recess. Air may pass inward through the radially outside openings, and then up through the chimney via the radially inward openings.
In other preferred forms, the recess includes a central depression for receiving the flame source, the flame source is a cup containing a candle, and the cup has a bottom with a recess sized to receive an upwardly extending mounting post of the cover. The support can optionally have a collector tray suspended below a top wall opening of the support so as to collect ashes, and/or the support top wall can include a recessed central section having no vertical openings there through, and a radially outward section having an opening there through.
The additional heat which builds up due to air flow through outer peripheral openings can be taken advantage of. There can be a faster release of active near the outside of the coil (as that portion is exposed to more heat). This enables an area to be adequately treated very soon after the device is lit. If desired, this effect can be enhanced by providing a higher concentration of active (per unit mass) near the outer periphery, and/or two different types of active (the more potent being on the outer periphery).
In another aspect, the invention provides a kit providing a replacement coil and candle for lamps of the above kind. A cup for housing the candle (e.g. one which interfits with the base) may also be supplied with the kit.
Still another aspect of the invention provides a method for controlling flying insects. One provides a lamp of the above kind, lights the coil and the flame source, and permits volatizable material to pass from the coil and out the chimney so as to expose an area to the volatizable material. The volatizable material is an insect control agent.
Preferred insect control agents are insecticides, repellents, and insect growth regulators. A wide variety of insect control agents of this type are known. The preferred ones are those which have previously been incorporated into mosquito coils, such as d-cis/trans allethrin.
Because the lamp provides both light and insect control, and does so even in windy environments, it is particularly suitable for use during a backyard barbecue, around sunset. The device is designed to utilize extremely inexpensive consumables (e.g. standard conventional burnable coils; standard wax candles).
The flame source serves multiple purposes. It provides light, while also creating convection to draw outside air past the burning coil. The air/volatile mix is then propelled out the top of the chimney to widely and quickly disperse the active.
The foregoing and other advantages of the present invention will appear from the following description. In that description, reference is made to the accompanying drawings which form a part hereof and in which there is shown by way of illustration preferred embodiments of the invention. These embodiments do not represent the full scope of the invention. Rather, reference should be made to the claims for interpreting the full scope of the invention.